Labor sources have told the ABC the choice of venue was deliberate by Mr Shorten, who wanted a location that not only spoke to the party but also to the nation, harking back to the calls for generational change that marked Mr Whitlam's ascendancy to the top job.

Get a wrap of the key stories and analysis from the ABC's chief politics writer Annabel Crabb.

Speaking in Canberra, Mr Morrison used an address to the National Press Club to argue now was not the time for Australia to turn back to Labor.

"Now is the time to get on and keep on with the work of building our economy, by backing in the choices Australians are wanting to make every day and to enable them to plan for their future with confidence," the Prime Minister said.

"Labor are proposing a big-taxing, big-spending agenda, once again at a time when Australians can least afford the bill that they will be forced to pay, not just over the next three years, but at least the next decade."

Mr Shorten's speech focused on issues he believed the nation was grappling with.

"I promise that we will send a message to the world, that when it comes to climate change Australia is back in the fight," he said.

"It is not the Australian way to avoid and duck the hard fights. We will take this emergency seriously, and we will not just leave it to other countries or to the next generation."

The criticism was twofold — that the Liberal and National parties have not done enough to combat climate change, and that some members of the Coalition refuse to accept climate science.

Carbon emissions and the environment have been front and centre of Mr Shorten's pitch to voters across the country, but particularly in the progressive state of Victoria and further north in Queensland, where he has argued the effects of climate change have been seen firsthand with damage to pristine environments such as the Great Barrier Reef.